http://www.ck12.org Chapter 1. An Introduction to Independent Events - Basic
Probability(success) =
number o f ways to get success
total number o f possible outcomesOdds(success) =number o f ways to get success
number o f ways to not get successWhat do you see as the difference between the two formulas? Let’s look at an example.
Example 1:Imagine you are rolling a die.
(a) Calculate the probability of rolling a “5.”
(b) Calculate the odds of rolling a “5.”
Solution:
(a) Probability(success) =total number o f possible outcomesnumber o f ways to get success
(b) Odds(success) =number o f ways to not get successnumber o f ways to get success
So now we can calculate the probability and we know the difference between probability and odds. Let’s move
one step further. Imagine now you were rolling a die and tossing a coin. What is the probability of rolling a 5 and
flipping the coin to get heads?